I first wrote about Hoodia in my “SkepDoc” column in Skeptic magazine (Vol. 13, No. 1, 2007). The following is adapted from that column with an update from new research revealing that it doesn’t work and that it causes worrisome side effects.

I first heard of Hoodia in 2006, when a radio ad informed me that it was the new miracle weight loss pill. Shortly after that, I started seeing ads for Hoodia everywhere. Anna Nicole Smith took it. It was featured on Oprah. Lesley Stahl went to Africa to taste the plant on 60 Minutes. There are nearly 40 competing brands of pills, a patch version, and even a Hoodia lollipop. It seems to have taken the world by storm; but it’s not new.

Hoodia gordonii is a cactus that grows in the deserts of southern Africa, and the San people have traditionally used it as an appetite suppressant, thirst quencher and to treat severe abdominal cramps, hemorrhoids, tuberculosis, indigestion, hypertension and diabetes. The claim is that it banishes hunger and thirst. What is the evidence? At this point it’s strictly anecdotal. Skinny Bushmen report it relieves hunger pangs in starvation conditions on long hunts; we don’t know what happens if it’s used by lazy fat people with access to food. Before the new study, there hadn’t been a single published study in humans. (more…)